tiles = {
         front = { "data/sprites/gialdini/front.bmp" },
         back  = { "data/sprites/gialdini/back.bmp" },
         left  = { "data/sprites/gialdini/left.bmp" },
         right  = { "data/sprites/gialdini/right.bmp" },
         walk_front = {
                       "data/sprites/gialdini/front.bmp",
                       "data/sprites/gialdini/walk_front.bmp"
                      },
         walk_back  = {
                       "data/sprites/gialdini/back.bmp",
                       "data/sprites/gialdini/walk_back.bmp"
                      },
         walk_left  = {
                       "data/sprites/gialdini/left.bmp",
                       "data/sprites/gialdini/walk_left.bmp"
                      },
         walk_right  = {
                       "data/sprites/gialdini/right.bmp",
                       "data/sprites/gialdini/walk_right.bmp"
                      }
        }
